JP5499313B2 - Transponder, relay device, and terminal device - Google Patents

Description

  The present invention relates to a transponder that converts bidirectionally between a client side signal and a transmission line side signal, and more particularly to a transponder that determines a connection destination of an interface that inputs and outputs a client side signal.

  In a transmission system (optical transmission system) in which a client device and a client device opposite to the client device are connected via a transmission line, when a failure occurs in the transmission line, the client device is notified of the failure. There is a need to.

  This transmission system is provided with two terminal devices connected to two client devices, and these terminal devices are known to be connected via a transmission line. This terminal device includes one transponder that performs bidirectional conversion between a client side signal used for communication with the client device and a transmission path side signal used for communication with the transmission path. When a signal is output from the client device, the transponder of the terminal device connected to the client device converts the client side signal into a transmission path side signal and outputs it to the transmission path side. On the other hand, when a signal is input to the client device, the transponder converts the transmission path side signal into a client side signal and the signal is input to the client device.

  Further, since the length of one transmission line is determined, the length of the transmission line can be increased by providing at least one relay device between the two terminal devices. This is because two transmission lines are connected to one relay device. This relay device includes two transponders. One transponder converts a transmission path side signal into a client side signal, and the other transponder converts a client side signal output from one transponder into a transmission path side signal.

  The transponder includes a client side interface connected to a client device or another transponder, and a transmission path side interface connected to a transmission path.

  The client side interface of the transponder provided in the terminal device is connected to the client device, and the transmission path side interface is connected to the transmission path. The client side interface provided in the relay apparatus is connected to the other transponder, and the transmission path side interface is connected to the transmission path.

  In the following, the term “communication device” will be used when the terminal station device and the relay device are collectively referred to.

  Here, in the transmission system described above, as a method of notifying the client device of the occurrence of a failure, a method of including failure information indicating that a failure has occurred in the overhead part of the optical signal, and a frame for transferring the failure information include: A method of generating and transferring the frame to a client device is known.

  For example, in the case of the former method, in an SDH (Synchronous Digital Hierarchy) system, failure information is transferred to a client device by including a signal called AIS (Alarm Indication Signal) in a frame of a transmission signal flowing through a transmission path.

  In the case of the latter method, in the Ethernet (registered trademark) system of 10 Gigabit Ethernet (Ethernet is a registered trademark), a failure transfer function called LFS (Link Fault Signaling) is standardized.

  However, in order for the communication device to detect such failure information, it is necessary to decode the optical signal at high speed and read out the alarm signal. For this reason, there exists a problem that the price of a communication apparatus will rise.

  On the other hand, if a failure occurs in order to reduce the price of the communication device, the client side interface of the transponder notifies the client device of the failure by stopping the output of the optical signal, and the failure on the transmission path side interface. There is known a method of outputting a client input disconnect signal that notifies that the occurrence of the error has occurred using an Ether-OAM signal (see, for example, Patent Document 1).

  This method will be described with reference to FIGS.

  FIG. 10 is an explanatory diagram of a failure notification method when a failure occurs in the transmission line of the conventional example.

  The transmission system includes a client device 100, a terminal device 200, a terminal device 500, and a client device 600. The terminal station devices 200 and 500 are connected via a transmission line 440.

  The terminal device 200 includes a transponder 420 and an optical multiplexer 430. The transponder 420 converts the client side signal from the client device 100 into a transmission path side signal. The optical multiplexer 430 combines the transmission path side signals from the transponder 420 and outputs the combined signals to the transmission path 440 side.

  The terminal device 500 includes a transponder 460 and an optical demultiplexer 450. The optical demultiplexer 450 demultiplexes the transmission path side signal from the transmission path 440 and outputs it to the transponder 460. The transponder 460 converts the transmission path side signal output from the optical demultiplexer 450 into a client side signal, and outputs the converted client side signal to the client apparatus 600.

  Here, it is assumed that a failure such as an optical fiber being cut occurs in the transmission line 440 (51). In this case, the optical signal does not reach downstream from the location where the failure occurred. For this reason, the transponder 460 provided in the terminal device 500 detects the disconnection (52), and stops the output from the client side interface connected to the client device 600 (53). The client device 600 detects an input interruption (54), and can detect that some kind of failure has occurred in the transmission system.

  FIG. 11 is an explanatory diagram of a failure notification method when a failure occurs between the client device 100 and the terminal device 200 of the conventional example.

  The configuration of the transmission system shown in FIG. 11 is the same as the configuration of the transmission system shown in FIG.

  When a failure such as an optical fiber cut occurs between the client device 100 and the terminal device 200 (51), the optical signal does not reach downstream from the failure occurrence location. For this reason, the transponder 420 provided in the terminal device 200 detects an input interruption (52), and outputs a client input interruption signal from the transmission path side interface to the downstream side (55).

  When the client input cutoff signal from the transponder 420 is input to the transponder 460, the transponder 460 stops output from the client side interface connected to the client device 600 (53). The client device 600 detects an input interruption (54), and can detect that some kind of failure has occurred in the transmission system.

  FIG. 12 is an explanatory diagram of a failure notification method in a conventional multistage transmission system.

  The transmission system shown in FIG. 12 is a multistage transmission system that includes two relay apparatuses 300 and 400 (hereinafter collectively referred to as the relay apparatus 300) and extends the transmission path. If at least one relay device 300 is provided, it is called a multistage transmission system.

The client devices 100 and 600 shown in FIG. 12 are the same as the client devices 100 and 600 shown in FIG. 10, and the terminal devices 200 and 500 shown in FIG. 12 are the same as the terminal devices 200 and 500 shown in FIG. Since there is, description is abbreviate | omitted.

  The relay apparatus 300 includes an optical demultiplexer 640, a transponder 650, a transponder 660, and an optical multiplexer 670.

  The optical demultiplexer 640 is the same as the optical demultiplexer 450 included in the terminal station device 500 shown in FIG. 10, and the optical multiplexer 670 is the same as the optical multiplexer 430 included in the terminal station device 200 shown in FIG. The description is omitted.

  The transponder 650 has a transmission path side interface connected to the optical demultiplexer 640 and a client side interface connected to the transponder 660, and converts the transmission path side signal into a client side signal.

Transponder 660 is connected the transmission line side interface to the optical multiplexer 67 0, the client-side interface is connected to the transponder 650 converts the client signal to the transmission line side signal.

  Note that the relay device 400 has the same configuration as the relay device 300, and thus description thereof is omitted.

  Here, when a failure such as an optical fiber cut occurs between the client device 100 and the terminal device 200 (810), the optical signal does not reach downstream from the failure occurrence location. For this reason, the transponder 420 included in the terminal device 200 detects an input disconnection (820), and outputs a client input disconnection signal from the transmission path side interface (830).

  When the client input disconnect signal is input to the transponder 650 included in the relay apparatus 300, the transponder 650 stops the output of the client side interface (840).

  The transponder 660 detects an input disconnection when the transponder 650 stops outputting the client side interface (850), and outputs a client input disconnection signal from the transmission path side interface (860).

  When the client input disconnect signal is input to the transponder 690 included in the relay apparatus 400, the transponder 690 stops the output of the client side interface (870).

  The transponder 700 detects an input disconnection when the transponder 690 stops the output of the client side interface (880), and outputs a client input disconnection signal from the transmission path side interface (890).

  When the client input disconnect signal is input to the transponder 450 provided in the terminal device 500, the transponder 450 stops the output of the client side interface (900).

  The client device 600 detects an input interruption (910), and can detect that a failure has occurred in the transmission system.

JP 2010-81223 A

  The multistage transmission system shown in FIG. 12 stops the output to the client device from the viewpoint of sharing the transponders provided in the terminal station devices 200 and 500 and the transponders provided in the relay devices 300 and 400, and generates a failure. In order to notify, all the transponders stop the output of the client side interface when the client input disconnection signal is inputted to the transmission line side interface.

Because of this, all the transponders connected to the transmission line output a client input disconnect signal despite the occurrence of a failure at one point on the client side interface, so the administrator checks all client input disconnect signals. Therefore, it was difficult to identify the faulty part.

  An object of the present invention is to provide a transponder that makes a relay device and a terminal device have a common transponder so that an administrator can easily identify a fault location.

A typical example of the present invention is a transponder that performs bidirectional conversion between a client side signal used for communication with a client device and a transmission path side signal used for communication with a transmission path. A client side interface for inputting / outputting the client side signal, and a transmission path side interface for inputting / outputting the transmission path side signal, and the client side interface includes any one of the other client side interface and the client device. A connection determination unit that determines which of the other client-side interface and the client device is connected to the client-side interface, and notifies the state of the transmission line that outputs a signal to the transmission line-side interface the channel state signal from the transmission path If input to the interface, and a transmitting signal generating unit for outputting a transmitting signal indicating that said status signal is inputted from the client-side interface to the other client-side interface or the client device, the connection determination A recognition signal output unit configured to output a recognition signal for determining that the other client side interface is connected to the client side interface from the client side interface to the other client side interface, and If a signal is input to the client-side interface from the other client-side interface, and determines that the other client-side interface to the client-side interface is connected, the transmission signal generation unit, Based on the determination result by the serial connection determination unit, and changes the mode of transmission signal output from the client-side interface to the other client-side interface or the client device.

  ADVANTAGE OF THE INVENTION According to this invention, the transponder with which a relay apparatus and a terminal station apparatus are equipped can be made shared, and the transponder which makes easy the identification of the fault location by an administrator can be provided

It is a figure which shows the structure of the transmission system of embodiment of this invention. It is a block diagram which shows the structure of the terminal station apparatus of embodiment of this invention. It is a block diagram which shows the structure of the relay apparatus of embodiment of this invention. It is explanatory drawing of the conversion of the signal in the transmission system which is not provided with the relay apparatus of embodiment of this invention. It is explanatory drawing of the conversion of the signal in the multistage transmission system of embodiment of this invention. It is a block diagram which shows the structure of the transponder of embodiment of this invention. It is explanatory drawing of the failure notification method in the transmission system of embodiment of this invention. It is a sequence diagram until two transponders of an embodiment of the present invention judge back-to-back connection. It is a flowchart of the connection determination process by the transponder of embodiment of this invention. It is explanatory drawing of the failure notification method when a failure generate | occur | produces in the transmission line of a prior art example. It is explanatory drawing of the failure notification method when a failure generate | occur | produces between the client apparatus and terminal device of a prior art example. It is explanatory drawing of the failure notification method in the multistage transmission system of a prior art example.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  FIG. 1 is a diagram showing a configuration of a transmission system according to an embodiment of the present invention.

  The transmission system includes client apparatuses 1 and 6, terminal station apparatuses 2 and 5, and relay apparatuses 3 and 4, and connects the client apparatus 1 and the client apparatus 6 installed at two points apart from each other. is there.

  A signal from the client apparatus 1 to the client apparatus 6 is transmitted to the client apparatus 6 through the terminal station apparatus 2, the relay apparatus 3, the relay apparatus 4, and the terminal station apparatus 5. A signal from the client device 6 to the client device 1 is transmitted in the same manner.

  Further, the terminal station devices 2 and 5 and the relay devices 3 and 4 (hereinafter, these devices are collectively referred to as communication devices) are connected to the monitoring control device 8 via the monitoring network 7. The communication device outputs an alarm signal of the client input disconnection signal to another communication device and also outputs it to the monitoring network 7. Therefore, the monitoring control device 8 can monitor the alarm signal output from the communication device in real time.

  FIG. 2 is a block diagram showing the configuration of the terminal devices 2 and 5 according to the embodiment of the present invention.

  The terminal station apparatuses 2 and 5 (hereinafter collectively referred to as terminal station apparatuses) include transponders 11 to 13 (hereinafter collectively referred to as transponders), an optical multiplexer 14, an optical demultiplexer 15, and a monitoring control unit 16.

The transponder performs bi-directional conversion between a client side signal used for communication with the client apparatuses 1 and 6 (hereinafter collectively referred to as a client apparatus) and a transmission path side signal used for communication with the transmission path.

  Specifically, the transponder converts the client side signal from the client device into a transmission path side signal having a predetermined wavelength that can be wavelength-multiplexed, and outputs the signal to the optical multiplexer 14. In this case, the transponder may perform conversion by adding an error correction code and data for remote control.

  Further, the transponder converts the transmission path side signal output from the optical demultiplexer 15 into a client side signal and outputs it to the client apparatus.

  The transponder includes a client side interface for inputting and outputting client side signals and a transmission path side interface for inputting and outputting transmission path side signals.

  The optical multiplexer 14 multiplexes transmission path side signals from a plurality of transponders and outputs the combined signal to a transmission path composed of a single optical fiber.

  The optical demultiplexer 15 demultiplexes the signal input from the transmission path and outputs it to the transponder.

  The supervisory control unit 16 monitors the optical input / output levels and operation states of the transponders, optical multiplexers 14 and optical demultiplexers 15 provided in the terminal equipment, and detects a failure when it detects a failure. Send.

  FIG. 3 is a block diagram illustrating a configuration of the relay apparatuses 3 and 4 according to the embodiment of this invention.

  Hereinafter, the relay apparatuses 3 and 4 are collectively referred to as a relay apparatus.

  The relay device uses an optical amplifier that does not convert an optical signal between an optical signal and an electric signal, and uses an optical regenerative repeater that converts an optical signal to an electric signal and then converts the electric signal to an optical signal. Although the method is known, the relay apparatus of this embodiment is configured by connecting the client side interfaces of two transponders. The connection between the client side interface of a transponder and the client side interface of another transponder is called a back-to-back connection.

  The relay device includes an optical demultiplexer 21 and an optical demultiplexer 30, optical multiplexers 22 and 29, transponders 23 to 28, and a monitoring control unit 31.

  The optical demultiplexer 21 and the optical demultiplexer 30 demultiplex the signal input from the transmission path and output it to the transponder. The optical demultiplexer 21 demultiplexes the signal from the first transmission path, and the optical demultiplexer 30 demultiplexes the signal from the second transmission path.

  The optical multiplexers 22 and 29 multiplex signals from a plurality of transponders and output the combined signals to the transmission path. The optical multiplexer 22 combines the signals from the transponders 23, 25, and 27, and outputs the combined signal to the first transmission path. The optical multiplexer 29 combines the signals from the transponders 24, 26, and 28, and outputs the combined signal to the second transmission path.

  The client side interface of the transponder 23 and the client side interface of the transponder 24 are connected.

  For example, when a signal is input from the first transmission line side, the signal is demultiplexed by the optical demultiplexer 21, and the demultiplexed signal is input to the transmission line side interface of the transponder 23. The transponder 23 converts the signal into a client side signal, and outputs the converted signal from the client side interface to the transponder 24.

  The transponder 24 converts the signal converted into the client side signal into a transmission line side signal, and outputs the converted signal from the transmission line side interface to the optical multiplexer 29. The optical multiplexer 29 combines the signal from the transponder 24 with the signals from the other transponders 26 and 28 and outputs the combined signal to the second transmission path.

  Even if a signal is input from the second transmission line to the transponder 24, the same signal conversion process is executed. The same applies to the transponders 25 and 26 and the transponders 27 and 28.

  The supervisory control unit 31 monitors the optical input / output levels, operation states, etc. of the transponders, optical multiplexers 22 and 29, and optical demultiplexers 21 and 30 provided in the relay device. Send an input disconnect signal.

  Next, signal conversion according to the present invention will be described with reference to FIGS.

  FIG. 4 is an explanatory diagram of signal conversion in a transmission system that does not include the relay device according to the embodiment of this invention.

  In the transmission system shown in FIG. 4, the terminal station devices 2 and 5 are connected via a transmission path 44. The terminal device 2 is connected to the client device 1, and the terminal device 5 is connected to the client device 6.

  A signal (client side signal) from the client apparatus 1 is input to the client side interface of the transponder 42. The transponder 42 converts the client-side signal input to the client-side interface into a transmission path-side signal, and outputs the signal to the optical multiplexer 43 from the transmission path-side interface. The optical multiplexer 43 combines the input transmission path side signal with the transmission path side signals of other wavelengths, and outputs them to the transmission path.

  The transmission path side signal output to the transmission path is input to the optical demultiplexer 45 provided in the terminal device 5. The optical demultiplexer 45 demultiplexes the input transmission line side signal to a predetermined wavelength and outputs it to the transmission line side interface of the transponder 46.

  When a transmission path side signal is input from the transmission path side interface, the transponder 46 converts the input transmission path side signal into a client side signal and outputs the client side signal to the client device 6 from the client side interface.

  FIG. 5 is an explanatory diagram of signal conversion in the multistage transmission system according to the embodiment of this invention.

  In the multistage transmission system shown in FIG. 5, two transponders are back-to-back connected in the relay apparatus. In this way, when a relay device is configured by connecting two transponders back-to-back, the transponder can be shared with other communication devices as compared with a relay device using an optical amplifier. The transmission path constituting the network can be extended.

  Among the configurations of the multistage transmission system shown in FIG. 5, the same configurations as those of the transmission system shown in FIG.

  The transmission path side signal output from the optical multiplexer 43 of the terminal station apparatus 2 is input to the optical demultiplexer 64 of the relay apparatus 3 via the transmission path.

  The optical demultiplexer 64 demultiplexes the input transmission line side signal to a predetermined wavelength and outputs it to the transmission line side interface of the transponder 65.

  The transponder 65 converts the transmission path side signal input to the transmission path side interface into a client side signal, and outputs the converted client side signal from the client side interface to the transponder 66.

  The transponder 66 converts the client side signal input to the client side interface into a transmission path side signal, and outputs the converted transmission path side signal to the optical multiplexer 67 from the transmission path side interface.

  The optical multiplexer 67 combines the input transmission path side signal with the transmission path side signals of other wavelengths and outputs them to the transmission path.

  The signal conversion in the relay device 4 is the same as the signal conversion in the relay device 3 described above, and a description thereof will be omitted.

  FIG. 6 is a block diagram showing the configuration of the transponder according to the embodiment of the present invention.

  The transponder includes optical modules 91 and 93, an FEC (Forward Error Correction) circuit 92, a recognition signal insertion circuit 94, a recognition signal detection circuit 95, a control circuit 96, and a failure transmission signal insertion circuit 97.

  The optical module 91 is connected to the FEC circuit 92, and the FEC circuit 92 is connected to the optical module 93. The recognition signal insertion circuit 94 and the failure transmission signal insertion circuit (transmission signal generation unit) 97 are connected to a connection line that outputs a signal to the optical module 93 among the connection lines that connect the FEC circuit 92 and the optical module 93. . The recognition signal detection circuit 95 is connected to a connection line that outputs a signal to the FEC circuit 92 among connection lines connecting the FEC circuit 92 and the optical module 93.

  The optical module 91 functions as a transmission path side interface for inputting and outputting transmission path side signals, and converts the transmission path side signals, which are optical signals, into electrical signals.

  The optical module 93 functions as a client-side interface that inputs and outputs client-side signals, and converts client-side signals that are optical signals into electrical signals.

  The FEC circuit 92 encodes and decodes an error correction code (FEC) included in the transmission line side signal.

  The recognition signal insertion circuit 94 inserts a recognition signal output from the client side interface into the signal.

  The recognition signal detection circuit 95 detects a recognition signal from the signal input to the client side interface. When the recognition signal detection circuit 95 detects a recognition signal from the signal input to the client side interface, the recognition signal detection circuit 95 notifies the control circuit 96 that the recognition signal has been detected.

  The recognition signal detection circuit 95 detects a failure transmission signal from the signal input to the client side interface. When the failure signal is detected from the signal input to the client side interface, the recognition signal detection circuit 95 notifies the control circuit 96 that the failure signal has been detected.

  The control circuit 96 controls various circuits. When notified from the recognition signal detection circuit 95 that the recognition signal has been detected, the control circuit 96 determines that the client side interface is a back-to-back connection in which another client side interface is connected, and the client side interface Outputs an ACK signal.

  In addition, when the control signal 96 is notified from the recognition signal detection circuit 95 that a failure transmission signal has been detected, the control circuit 96 transmits a client input disconnection transmission signal indicating that a failure has occurred upstream from itself. Output from.

  As described above, the recognition signal insertion circuit 94, the recognition signal detection circuit 95, the control circuit 96, and the failure transmission signal insertion circuit 97 determine whether or not another client side interface is connected to the client side interface. It becomes.

  In addition, the recognition signal detection circuit 95 and the control circuit 96 of the connection determination unit serve as a response signal generation unit that outputs an ACK signal that is a response signal to the recognition signal from the client side interface.

  When it is determined that the back-to-back connection is established, the failure transmission signal insertion circuit 97 outputs a failure transmission signal from the client side interface when detecting the client input cutoff signal or the client input cutoff transmission signal from the transmission path side interface. On the other hand, when it is determined that the back-to-back connection is not established, the failure transmission signal insertion circuit 97 detects the client input disconnection signal or the client input disconnection transmission signal at the transmission line side interface, thereby stopping the output of the client side interface. Output a transmission signal. The client input cutoff signal is a signal output from the transmission path side interface when an input cutoff is detected at the client side interface.

  In this way, the transponder connected back-to-back does not stop the output of the client side interface and transmits a transmission signal even when a failure occurs upstream from the transmission path side interface of the transponder. Unnecessary client input disconnection signal output can be suppressed.

  As described above, when the failure transmission signal insertion circuit 97 detects the client input disconnection signal or the client input disconnection transmission signal at the transmission line side interface, the failure transmission signal output from the client side interface based on the determination result of the connection determination unit. Change the aspect of the signal.

  FIG. 7 is an explanatory diagram of a failure notification method in the transmission system according to the embodiment of this invention.

  The configuration of the transmission system shown in FIG. 7 is the same as that of the transmission system shown in FIG.

  When a failure such as an optical fiber break occurs between the client device 1 and the terminal device 2 (81), the transponder 42 provided in the terminal device 2 detects the input disconnection (82), and the transmission path side interface A client input disconnect signal is output from (83). The client input cutoff signal is also output to the monitoring network 7 as an alarm signal.

  Next, when the client input disconnect signal is input to the transmission path side interface, the transponder 65 provided in the relay device 3 outputs the transmission signal from the client side interface because the transponder 65 is connected back to back with the transponder 66. (84).

  When a transmission signal is input to the client side interface, the transponder 66 included in the relay device 3 outputs a client input disconnection transmission signal for notifying the downstream side that a failure has occurred from the transmission path side interface to the transmission path ( 85). Note that the client input disconnection transmission signal is not output to the monitoring network 7 as an alarm signal.

Next, when the client input disconnection transmission signal is input to the transmission path side interface, the transponder 69 provided in the relay device 4 is connected back-to-back with the transponder 70, so that the transmission signal is transmitted from the client side interface. Output ( 86A ).

When a transmission signal is input to the client side interface, the transponder 70 provided in the relay device 4 outputs a client input disconnection transmission signal from the transmission path side interface to the transmission path (86 B ).

  Next, when a client input disconnection transmission signal is input to the transmission path side interface, the transponder 46 provided in the terminal device 5 stops output of the client side interface because the transponder 46 is not connected back-to-back ( 87).

  Then, the client device 6 can detect that a failure has occurred in the transmission system by detecting input interruption (88).

  As described above, in this embodiment, when a signal (client input disconnection signal or client input disconnection transmission signal) indicating that a failure has occurred is input to the transmission path side interface of the transponder, the transponder is connected back-to-back. If so, the transmission signal is output from the client side interface. Further, if the transponder is not connected back-to-back, that is, if a client device is connected to the client-side interface, output stops. Therefore, it is possible to prevent a transponder connected back-to-back to the transponder from detecting an input disconnection at the client side interface and outputting a client input disconnection signal from the transmission path side interface.

  As a result, the administrator of the monitoring control device 8 can easily identify that a failure has occurred upstream of the device that has output the client input disconnect signal.

  In FIG. 7, it has been described that a failure has occurred between the client device 1 and the terminal device 2. Next, a case where a failure has occurred in the transmission path between the terminal device 2 and the relay device 4. This will be described with reference to FIG.

  Since no signal is input to the transmission path side interface of the transponder 65 of the relay device 3, the transponder 65 detects an input interruption at the transmission path side interface. In this case, the transponder 65 stops the output of the client side interface.

  That is, the transponder of this embodiment stops the output of the client side interface when detecting an input disconnection at the transmission path side interface, and outputs a client input disconnection signal from the transmission path side interface when detecting an input disconnection at the client side interface. Is set to

  Since the output of the client side interface of the transponder 65 is stopped, the transponder 66 outputs a client input cutoff signal from the transmission path side interface when detecting an input cutoff at the client side interface.

  Subsequent processing is the same as that when a failure occurs between the client device 1 and the terminal device 2, and a description thereof will be omitted.

  Thus, even if an input disconnection is detected at the transponder's transmission line side interface, the output of the transponder's client side interface is stopped, so the client input disconnection signal is sent from the transponder's transmission line side interface connected back-to-back to the transponder. Is output. Since the transponder downstream from the transponder that has output the client input disconnect signal does not output the client input disconnect signal, the administrator can easily identify the fault location.

  FIG. 8 is a sequence diagram until the two transponders 65 and 66 according to the embodiment of the present invention determine the back-to-back connection.

  Each transponder shown in FIG. 8 corresponds to each transponder shown in FIG. In FIG. 8, since the relay device 4 is omitted, it is assumed that the transponder 46 of the terminal device 5 is connected to the transponder 66 provided in the relay device 3.

  First, power is turned on to the transponder 65 (100). If the connection between the transmission path side interface of the transponder 65 and the transponder 42 is not established, nothing is input to the transmission path side interface of the transponder 65 (102), and the transponder 65 stops the output of the client side interface (101).

  In addition, as a case where the connection between the transmission path side interface of the transponder 65 and the transponder 42 is not established, for example, when the optical fiber that connects the transmission side interface of the transponder 65 and the transmission side interface of the transponder 42 is not connected, And the case where the power is not supplied to the transponder 42 etc. can be considered.

  Next, when the connection between the transmission path side interface of the transponder 42 and the transmission path side interface of the transponder 65 is established, the transponder 42 outputs a signal from the transmission path side interface, and the transponder 65 receives a signal input to the transmission path side interface. When this is detected, it is determined that the connection between the transmission path side interface and the transponder 42 has been established (103). Then, the transponder 65 outputs a regular signal from the client side interface (104). Unlike the recognition signal, the regular signal is a signal that can be detected by the transponder regardless of whether it is input to the client side interface of the transponder or the transmission path side interface.

  Similar to the connection between the transponder 42 and the transponder 65, if no connection is established between the transponder 46 and the transponder 66, nothing is input to the transmission path side interface of the transponder 66 (105). When a signal is input to the transmission path side interface, it is determined that the connection between the transponder 46 and the transponder 66 has been established (106). Then, the transponder 66 outputs a normal signal from the client side interface (107).

  The transponders 65 and 66 confirm that the link between both client side interfaces has been established by inputting the output signal.

  When a regular signal is input from the other transponder to the client side interface, one transponder outputs a recognition signal from the client side interface (108). In FIG. 8, the transponder 66 outputs a recognition signal first because a normal signal is input earlier than the transponder.

  When the recognition signal is input to the client side interface, the transponder determines that the connection is back-to-back and outputs an ACK signal from the client side interface (109).

  Note that even if the recognition signal is input to the transmission path side interface, the recognition signal detection circuit 95 shown in FIG. 6 does not detect the recognition signal, so the transponder does not output the ACK signal. This is because the recognition signal is composed of a special pattern that is not used for a normal signal.

  In this way, the transponders 65 and 66 determine whether or not they are back-to-back connections, and when it is determined that they are back-to-back connections, the operation in the back-to-back mode is started (110, 111). ).

  Here, when a failure occurs between the client apparatus 1 and the terminal apparatus 2 as in FIG. 7, the transponder 42 detects that there is no input to the client side interface, and sends a client input disconnect signal from the transmission path side interface. Output (83).

Transponder 65, when the client input interruption signal is input to the transmission line side interface, since the transponder 65 and the transponder 66 are connected back to back, and outputs the transmission signal from the client-side interface (8 4).

When a transmission signal is input to the client side interface, the transponder 66 outputs a client input disconnection transmission signal from the transmission path side interface (8 5 ).

  When the client input disconnect signal is input to the transmission path side interface, the transponder 46 is not connected back-to-back, and stops output of the client side interface (87).

  FIG. 9 is a flowchart of connection determination processing by the transponder according to the embodiment of this invention.

  The connection determination process is executed at a predetermined timing for a predetermined time after the power is turned on by the control circuit 96 provided in the transponder.

  First, the control circuit 96 determines whether any signal is input to the transmission path side interface (901).

  If it is determined in step 901 that no signal is input to the transmission path side interface, the connection determination process is terminated because the connection on the transmission path side has not been established.

  On the other hand, if it is determined in the processing of step 901 that some signal has been input to the transmission path side interface, the control circuit 96 outputs a normal signal from the client side interface (902).

  Next, the control circuit 96 determines whether or not a regular signal is input to the client side interface (903).

  If it is determined in step 903 that no regular signal is input to the client side interface, the connection determination process is terminated because the connection on the client side has not been established.

  On the other hand, if it is determined in step 903 that a regular signal has been input to the client side interface, the control circuit 96 outputs a recognition signal from the client side interface (904).

  Next, the control circuit 96 determines whether or not a recognition signal corresponding to the recognition signal output in step 904 has been input to the client side interface (905).

  If it is determined in step 905 that the recognition signal has been input to the client side interface, it is determined that the connection is back-to-back (906), and the connection determination process is terminated.

  On the other hand, if it is determined in step 905 that the recognition signal is not input to the client-side interface, it is determined that the connection is not back-to-back (907), and the connection determination process is terminated.

  If it is determined in step 906 or 907 whether back-to-back connection is established, the connection determination process is not repeatedly executed.

  Further, in FIG. 9, it is determined whether or not the back-to-back connection is made depending on whether or not the recognition signal is input to the client side interface. If it is input, it is determined that the connection is back-to-back. If the ACK signal is not input, it may be determined that the connection is not back-to-back.

In the present embodiment, the notification of the failure occurring on the upstream side of the transponder has been described. However, the present invention is not limited to the failure, and the state (including the failure) on the upstream side of the transponder may be notified. In this case, the client input disconnection signal and the client input disconnection transmission signal shown in FIG. 7 are status signals.

  As described above, in this embodiment, the transponder outputs a recognition signal from the client side interface, and determines whether or not the back-to-back connection is made based on the recognition signal. In the case of back-to-back connection, when a status signal is input from the transmission line side interface, a transmission signal is output from the client-side interface.

  As a result, the transponders used for the relay device and the terminal device can be shared, an unnecessary client disconnect signal can be prevented from being output, and the failure location can be easily identified.

DESCRIPTION OF SYMBOLS 1 Client apparatus 2, 5 Terminal station apparatus 3, 4 Relay apparatus 6 Client apparatus 7 Monitoring network 8 Monitoring control apparatus

Claims (9)

A transponder that converts bidirectionally between a client side signal used for communication with a client device and a transmission line side signal used for communication with a transmission line,
A client side interface for inputting and outputting the client side signal;
A transmission path side interface for inputting and outputting the transmission path side signal,
Either the other client side interface or the client device is connected to the client side interface ,
A connection determination unit that determines which of the other client side interface and the client device is connected to the client side interface;
When a state signal for notifying a state on the transmission line side outputting a signal to the transmission line side interface is input from the transmission line to the transmission line side interface, a transmission signal indicating that the state signal is input is transmitted to the client. A transmission signal generation unit that outputs from the side interface to the other client side interface or the client device ,
The connection determination unit
A recognition signal output unit for outputting a recognition signal for determining that the other client side interface is connected to the client side interface from the client side interface to the other client side interface ;
When the recognition signal is input from the other client side interface to the client side interface, it is determined that the other client side interface is connected to the client side interface;
The transponder, wherein the transmission signal generation unit changes a mode of a transmission signal output from the client side interface to the other client side interface or the client device based on a determination result by the connection determination unit. The transmission signal generator is
If the connection determination unit determines that the other client side interface is connected to the client side interface, the transmission signal is output from the client side interface to the other client side interface ;
The output of a signal from the client side interface to the client device is stopped when the connection determination unit determines that the client device is connected to the client side interface. transponder.   The transponder according to claim 2, wherein the status signal is a failure signal that conveys that a failure has occurred on the transmission line side. The recognition signal output unit
When there is any signal input from the transmission line to the transmission line side interface, it is determined that a connection with the transmission line has been established,
When it is determined that the connection with the transmission path has been established, a predetermined signal different from the recognition signal is output from the client side interface to the other client side interface ,
Determines that connection to the transmission path is established, and the recognition when a predetermined signal from the other client-side interface to the client-side interface is inputted, from the client-side interface to the other client-side interface 4. The transponder according to claim 1, wherein the transponder outputs a signal. The connection determination unit
If the recognition signal is inputted to the client-side interface from the other client-side interface comprises a reply signal generator outputting a response signal with respect to the recognition signal from the client-side interface to the other client-side interface,
It is determined that the other client side interface is connected to the client side interface by inputting a response signal to the output recognition signal from the other client side interface to the client side interface. The transponder according to any one of claims 1 to 4.   A relay device that has two transponders according to claim 2 as a first transponder and a second transponder, and relays two transmission paths used for signal transmission from one client device to the other client device,
  The first transponder is connected to one transmission path for transmitting a signal from the one client device side to the first transponder;
  The second transponder is connected to the other transmission path for transmitting a signal from the second transponder to the other client device;
  A client side interface of the first transponder and a client side interface of the second transponder are connected;
  The relay apparatus, wherein the one transmission path is connected to the transmission path side interface of the first transponder, and the other transmission path is connected to the transmission path side interface of the second transponder. The status signal is a failure signal that conveys that a failure has occurred on the transmission line side,
The connection determination unit of the first transponder is
A recognition signal for outputting a recognition signal for determining that the client side interface of the second transponder is connected to the client side interface of the first transponder from the client side interface of the first transponder to the client side interface of the second transponder With an output section,
When the recognition signal is input from the client side interface of the second transponder to the client side interface of the first transponder, the client side interface of the second transponder is connected to the client side interface of the first transponder. Judgment,
The recognition signal output unit of the first transponder is
When there is any signal input from the one transmission path to the transmission path side interface of the first transponder, it is determined that the connection with the one transmission path is established,
If it is determined that the connection with the one transmission line has been established, a predetermined signal different from the recognition signal is output from the client side interface of the first transponder to the client side interface of the second transponder;
When it is determined that a connection with the one transmission path has been established and a predetermined signal is input from the client side interface of the second transponder to the client side interface of the first transponder, the client of the first transponder The relay apparatus according to claim 6, wherein the recognition signal is output from a side interface to a client side interface of the second transponder.   The connection determination unit of the first transponder is
  When the recognition signal is input from the client side interface of the second transponder to the client side interface of the first transponder, a response signal to the recognition signal is sent from the client side interface of the first transponder to the client side of the second transponder. It has a response signal generator that outputs to the interface,
  A response signal to the output recognition signal is input from the client side interface of the second transponder to the client side interface of the first transponder, so that the client side interface of the second transponder is connected to the client side interface of the first transponder. The relay device according to claim 7, wherein the relay device is determined to be connected.   A terminal device having one transponder according to claim 2 and connected to the client device and the transmission path,
  The terminal device transmits a signal received via the transmission path to the client device;
  The terminal device, wherein the client device is connected to the client side interface of the transponder, and the transmission path is connected to the transmission path side interface.

Images